[lldb] Fix step-avoid-regexp logging

[kastiglione]

Summary

Ensure step-avoid-regexp logs are emitted in the case where the regex has no
capture groups.

Without this change, the log is printed only if the regex has at least one
capture group.

Another change is to the log message: the first capture group has been removed
from the message. There could be zero capture groups, and there could be two or
more capture groups.

lldb/source/Target/ThreadPlanStepInRange.cpp

bool ThreadPlanStepInRange::FrameMatchesAvoidCriteria() {
   if (avoid_regexp_to_use != nullptr) {
     SymbolContext sc = frame->GetSymbolContext(
         eSymbolContextFunction | eSymbolContextBlock | eSymbolContextSymbol);
     if (sc.symbol != nullptr) {
       const char *frame_function_name =
           sc.GetFunctionName(Mangled::ePreferDemangledWithoutArguments)
               .GetCString();
       if (frame_function_name) {
-        llvm::SmallVector<llvm::StringRef, 2> matches;
-        bool return_value =
-            avoid_regexp_to_use->Execute(frame_function_name, &matches);
-        if (return_value && matches.size() > 1) {
-          std::string match = matches[1].str();
+        bool return_value = avoid_regexp_to_use->Execute(frame_function_name);
+        if (return_value) {
           LLDB_LOGF(GetLog(LLDBLog::Step),
-                    "Stepping out of function \"%s\" because it matches "
-                    "the avoid regexp \"%s\" - match substring: \"%s\".",
+                    "Stepping out of function \"%s\" because it matches the "
+                    "avoid regexp \"%s\".",
                     frame_function_name,
-                    avoid_regexp_to_use->GetText().str().c_str(),
-                    match.c_str());
+                    avoid_regexp_to_use->GetText().str().c_str());
         }
         return return_value;
       }
     }
   }
   return false;
 }